8. Dr. Yates is studying a rare brain disorder that only affects people's ability to remember faces. After years of searching, he's been able to enlist a total of five individuals with the disorder. He's planning on studying them in depth. The research method that he is most likely to use is the:

Select only one.
☐ Correlational method
☐ Survey method
☐ Case study method
☐ Naturalistic observation method